US5663090A - Method to thermally form hemispherical grain (HSG) silicon to enhance capacitance for application in high density DRAMs - Google Patents

Method to thermally form hemispherical grain (HSG) silicon to enhance capacitance for application in high density DRAMs Download PDF

Info

Publication number
US5663090A
US5663090A US08/496,722 US49672295A US5663090A US 5663090 A US5663090 A US 5663090A US 49672295 A US49672295 A US 49672295A US 5663090 A US5663090 A US 5663090A
Authority
US
United States
Prior art keywords
recited
silicon
silicon material
temperature
gas
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US08/496,722
Inventor
Charles H. Dennison
Randhir P. S. Thakur
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Micron Technology Inc
Original Assignee
Micron Technology Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Micron Technology Inc filed Critical Micron Technology Inc
Priority to US08/496,722 priority Critical patent/US5663090A/en
Assigned to MICRON TECHNOLOGY, INC. reassignment MICRON TECHNOLOGY, INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: DENNISON, CHUCK, THAKUR, RANDHIR P. S.
Priority to US08/842,302 priority patent/US5913127A/en
Assigned to MICRON TECHNOLOGY, INC. reassignment MICRON TECHNOLOGY, INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: DENNISON, CHARLES H., THAKUR, RANDHIR P.S.
Application granted granted Critical
Publication of US5663090A publication Critical patent/US5663090A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L28/00—Passive two-terminal components without a potential-jump or surface barrier for integrated circuits; Details thereof; Multistep manufacturing processes therefor
    • H01L28/40—Capacitors
    • H01L28/60—Electrodes
    • H01L28/82—Electrodes with an enlarged surface, e.g. formed by texturisation
    • H01L28/84—Electrodes with an enlarged surface, e.g. formed by texturisation being a rough surface, e.g. using hemispherical grains
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02365—Forming inorganic semiconducting materials on a substrate
    • H01L21/02367—Substrates
    • H01L21/0237—Materials
    • H01L21/02373—Group 14 semiconducting materials
    • H01L21/02381—Silicon, silicon germanium, germanium
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02365—Forming inorganic semiconducting materials on a substrate
    • H01L21/02436—Intermediate layers between substrates and deposited layers
    • H01L21/02439—Materials
    • H01L21/02441—Group 14 semiconducting materials
    • H01L21/0245—Silicon, silicon germanium, germanium
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02365—Forming inorganic semiconducting materials on a substrate
    • H01L21/02518—Deposited layers
    • H01L21/02521—Materials
    • H01L21/02524—Group 14 semiconducting materials
    • H01L21/02532—Silicon, silicon germanium, germanium
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02365—Forming inorganic semiconducting materials on a substrate
    • H01L21/02518—Deposited layers
    • H01L21/02587—Structure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02365—Forming inorganic semiconducting materials on a substrate
    • H01L21/02612—Formation types
    • H01L21/02617—Deposition types
    • H01L21/0262—Reduction or decomposition of gaseous compounds, e.g. CVD
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L28/00—Passive two-terminal components without a potential-jump or surface barrier for integrated circuits; Details thereof; Multistep manufacturing processes therefor
    • H01L28/40—Capacitors
    • H01L28/60—Electrodes
    • H01L28/82—Electrodes with an enlarged surface, e.g. formed by texturisation
    • H01L28/90—Electrodes with an enlarged surface, e.g. formed by texturisation having vertical extensions
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S438/00—Semiconductor device manufacturing: process
    • Y10S438/906—Cleaning of wafer as interim step
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S438/00—Semiconductor device manufacturing: process
    • Y10S438/964—Roughened surface

Definitions

  • This invention relates to semiconductor fabrication processing and more particularly to a process for forming HemiSpherical Grain (HSG) silicon.
  • HSG HemiSpherical Grain
  • the storage capacitance can be enhanced by using HemiSpherical Grain (HSG) silicon to form the storage node electrode without increasing the area required for the cell or the storage electrode height.
  • HSG HemiSpherical Grain
  • the available methods include the direct deposition of HSG polysilicon by Low Pressure Chemical Vapor Deposition (LPCVD) with the temperature optimized between amorphous silicon and polysilicon deposition temperatures, and HSG formation by subsequent high vacuum annealing.
  • LPCVD Low Pressure Chemical Vapor Deposition
  • FIG. 1 is a process flow diagram of an embodiment of the present invention forming hemispherical grain (HSG) silicon;
  • FIGS. 3a, 3b, 3c and 4a, 4b are cross-sectional views of an in-process wafer portion depicting the formation of HSG silicon on a silicon material.
  • An embodiment of the present invention is directed to a process for forming hemispherical grain (HSG) silicon as depicted by the process steps of FIG 1.
  • FIG. 2 shows formation of HSG silicon during a temperature cycle.
  • a process for forming hemispherical grained silicon on a silicon material is depicted.
  • a silicon material is heated in the presence of an H 2 ambient; at step 11, the silicon material is continues to be exposed to H 2 ambient gas or the material is exposed to a cleaning gas; and at step 12, the temperature of the silicon material is decreased while the silicon material is exposed to a silicon hydride gas.
  • the H 2 ambient at least be present for a period of time during the steady state period 21.
  • the silicon hydride gas may be present during the entire ramp down period 22 (or longer as shown by period 23), the silicon hydride gas must be present for at least a portion of the ramp down time period 22.
  • the H 2 ambient and the silicon hydride gas may overlap during any of the three cycles. It is preferred this thermal cycle is performed by rapid thermal processing or the thermal cycle is performed by a furnace that has a very fast heat ramp rate, such as furnaces having a ramp rate of 6° C./min to as high as 40° C./min.
  • the silicon hydride gas is diluted with an inert gas, such as Ar and N 2 .
  • the diluted silicon hydride gas is silane (SiH 4 ) which is diluted with approximately 2% argon.
  • Other silicon hydride gases, such as disilane (Si 2 H 6 ) may be substituted for silane.
  • silicon surface cleaning gas such as GeH 4 , NF 3 , vapor hydrofluoric acid or by using ultraviolet light in an ozone gas, during a temperature ranging from 25° C. to 1250° C.
  • FIGS. 3a, and 3b depict the resulting formation a hemispherical grained silicon surface such as on a capacitor plate (i.e., a storage cell capacitor plate).
  • a silicon layer 31 has been formed over supporting substrate 30.
  • FIG. 3b the structure of FIG. 3a is subjected to the process steps as depicted in FIG. 1 and the formation of HSG silicon 32 is the result.
  • Silicon layers 31 and 32 may be used to form a storage node to a storage cell.
  • FIG. 3c depicts a completed storage capacitor where an alternate Reactive Ion Etch (RIE) is performed on the structure of FIG. 3a and thus exposes the outside walls of silicon layer 31.
  • RIE alternate Reactive Ion Etch
  • a storage node cell plate made of HSG silicon 32 is subjected to the process steps depicted in FIG. 1 to form a storage node cell plate made of HSG silicon 32.
  • a dielectric layer 33 is formed on HSG silicon 32, followed by the formation of a second capacitor cell plate made of conductive layer 34.
  • FIGS. 4a and 4b depict the resulting formation a hemispherical gained silicon surface such as on a silicon plug.
  • a silicon plug 43 has been formed over a supporting substrate 40, interposed between patterned lines 42 and connecting to diffusion region 41.
  • a Reactive Ion Etch (RIE) is used to form the patterned silicon plug 43 having exposed outer sidewalls.
  • RIE Reactive Ion Etch
  • remaining silicon plug 43 is subjected to the process steps depicted in FIG. 1 to form a storage node cell plate made of HSG silicon 44.
  • a dielectric layer 45 is formed on HSG silicon 44, followed by the formation of a second capacitor cell plate made of conductive layer 46.
  • FIGS. 3a, 3b, 3c and 4a, 4b represent steps that may integrated into semiconductor wafer fabrication and in particular DRAM fabrication to form storage capacitors. Conventional steps know to those skilled in the art may be used to fabricate the wafer up to the construction of the structures of FIGS. 3a and 4a. In like manner, after the formation of the HSG silicon, as depicted in 3b, 3c and 4b, the wafer is completed using conventional fabrication process steps.

Abstract

An embodiment of the present discloses a thermal process for forming hemispherical grained silicon on a silicon material by the steps of: heating the silicon material to a steady state temperature; exposing the silicon material to a hydrogen containing ambient; and causing a decreasing temperature differential of the silicon material while exposing the silicon material to a silicon hydride gas. This embodiment is accomplished by using a thermal cycle having a temperature ramp up period, a temperature steady state period during at least a portion of which the H2 ambient is present and temperature ramp down period during at least a portion of which the diluted silicon hydride gas is present. A second embodiment discloses a process for forming a hemispherical grained silicon surface on at least one capacitor plate made of silicon material, by increasing the temperature of the capacitor plate in an H2 containing ambient; exposing a surface of the capacitor plate's silicon material to a cleaning gas (such as GeH4, NF3, using ultraviolet light in the presence of ozone gas, vapor hydrofluoric acid silicon hydride gas, and H2); and decreasing the temperature of the capacitor plate while exposing the capacitor plate to a silicon hydride gas.

Description

FIELD OF THE INVENTION
This invention relates to semiconductor fabrication processing and more particularly to a process for forming HemiSpherical Grain (HSG) silicon.
BACKGROUND OF THE INVENTION
The continuing trend of scaling down integrated circuits has forced the semiconductor industry to consider new techniques for fabricating precise components at submicron levels. Along with the need for smaller components, there has been a growing demand for devices requiring less power consumption. In the manufacture of transistors, these trends have led the industry to refine approaches to achieve thinner cell dielectric and gate oxide layers.
In dynamic semiconductor memory storage devices it is essential that storage node capacitor cell plates be large enough to retain an adequate charge (or capacitance) in spite of parasitic capacitance and noise that may be present during circuit operation. As is the case for most semiconductor integrated circuitry, circuit density is continuing to increase at a fairly constant rate. The issue of maintaining storage node capacitance is particularly important as the density of DRAM arrays continues to increase for future generations of memory devices.
The ability to densely pack storage cells while maintaining required capacitance levels is a crucial requirement of semiconductor manufacturing technologies if future generations of expanded memory array devices are to be successfully manufactured.
One method of maintaining, as well as increasing, storage node size in densely packed memory devices is through the use of "stacked storage cell" design. With this technology, two or more layers of a conductive material such as polycrystalline silicon (polysilicon or poly) are deposited over an access device on a silicon wafer, with dielectric layers sandwiched between each poly layer.
Though stacked (capacitor) storage cells are promising candidates to achieve sufficient storage capacitance in a limited area, as the DRAM cell size shrinks scaling of the stacked capacitor structures is becoming more difficult.
Conventionally, it is known that the storage capacitance can be enhanced by using HemiSpherical Grain (HSG) silicon to form the storage node electrode without increasing the area required for the cell or the storage electrode height. The available methods include the direct deposition of HSG polysilicon by Low Pressure Chemical Vapor Deposition (LPCVD) with the temperature optimized between amorphous silicon and polysilicon deposition temperatures, and HSG formation by subsequent high vacuum annealing.
U.S. Pat. No. 5,278,091 and U.S. Pat. No. 5,278,091, having a common assignee, having related subject matter, are hereby incorporated by reference.
SUMMARY OF THE INVENTION
An embodiment of the present invention teaches a process for forming hemispherical grained silicon on a silicon material by:
heating the silicon material in an H2 ambient;
presenting a cleaning gas to the silicon material; and
decreasing the temperature of the silicon material while exposing the silicon material to a silicon hydride gas.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a process flow diagram of an embodiment of the present invention forming hemispherical grain (HSG) silicon;
FIG. 2 shows formation of HSG silicon during a temperature cycle; and
FIGS. 3a, 3b, 3c and 4a, 4b are cross-sectional views of an in-process wafer portion depicting the formation of HSG silicon on a silicon material.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
An embodiment of the present invention is directed to a process for forming hemispherical grain (HSG) silicon as depicted by the process steps of FIG 1. FIG. 2 shows formation of HSG silicon during a temperature cycle. FIGS. 3a, 3b and 4a, 4b depict the formation of HSG silicon on a silicon material.
Referring now to FIG. 1, a process for forming hemispherical grained silicon on a silicon material is depicted. At step 10, a silicon material is heated in the presence of an H2 ambient; at step 11, the silicon material is continues to be exposed to H2 ambient gas or the material is exposed to a cleaning gas; and at step 12, the temperature of the silicon material is decreased while the silicon material is exposed to a silicon hydride gas.
In accordance with the graph depicted in FIG. 2, it is preferred that the process steps be performed in the order that is outlined in FIG. 1. A silicon material, such as polysilicon, or amorphous silicon hemispherical grained silicon, preferably conductively doped with conductive impurities (either introduced in situ during formation of the silicon material or introduced into the silicon material by implantation after the silicon material is formed) is subjected to a thermal cycle having a temperature ramp up period 20, a temperature steady state period (with temperature ranging from approximately 500° C. to 1100° C.) and temperature ramp down period 22 during at least a portion of which the diluted silicon hydride gas is present. The H2 ambient may be present during the entire ramp up period 20, as well as during the entire steady state period 21. However, it is preferred the H2 ambient at least be present for a period of time during the steady state period 21. Also, though the silicon hydride gas may be present during the entire ramp down period 22 (or longer as shown by period 23), the silicon hydride gas must be present for at least a portion of the ramp down time period 22. Also, if so desired, the H2 ambient and the silicon hydride gas may overlap during any of the three cycles. It is preferred this thermal cycle is performed by rapid thermal processing or the thermal cycle is performed by a furnace that has a very fast heat ramp rate, such as furnaces having a ramp rate of 6° C./min to as high as 40° C./min.
In one embodiment of the present invention, the silicon hydride gas is diluted with an inert gas, such as Ar and N2. In a preferred embodiment, the diluted silicon hydride gas is silane (SiH4) which is diluted with approximately 2% argon. Other silicon hydride gases, such as disilane (Si2 H6) may be substituted for silane.
It may also prove advantageous to preclean the silicon material prior to the heating of the silicon material by subjecting the silicon material to a silicon surface cleaning gas, such as GeH4, NF3, vapor hydrofluoric acid or by using ultraviolet light in an ozone gas, during a temperature ranging from 25° C. to 1250° C.
FIGS. 3a, and 3b depict the resulting formation a hemispherical grained silicon surface such as on a capacitor plate (i.e., a storage cell capacitor plate). Referring now to FIG. 3a, a silicon layer 31 has been formed over supporting substrate 30. Referring now to FIG. 3b, the structure of FIG. 3a is subjected to the process steps as depicted in FIG. 1 and the formation of HSG silicon 32 is the result. Silicon layers 31 and 32 may be used to form a storage node to a storage cell. FIG. 3c depicts a completed storage capacitor where an alternate Reactive Ion Etch (RIE) is performed on the structure of FIG. 3a and thus exposes the outside walls of silicon layer 31. After performing the RIE, remaining silicon layer 31 is subjected to the process steps depicted in FIG. 1 to form a storage node cell plate made of HSG silicon 32. To complete the storage capacitor a dielectric layer 33 is formed on HSG silicon 32, followed by the formation of a second capacitor cell plate made of conductive layer 34.
FIGS. 4a and 4b depict the resulting formation a hemispherical gained silicon surface such as on a silicon plug. Referring now to FIG. 4a, a silicon plug 43 has been formed over a supporting substrate 40, interposed between patterned lines 42 and connecting to diffusion region 41. A Reactive Ion Etch (RIE) is used to form the patterned silicon plug 43 having exposed outer sidewalls. After performing the RIE, remaining silicon plug 43 is subjected to the process steps depicted in FIG. 1 to form a storage node cell plate made of HSG silicon 44. To complete the storage capacitor a dielectric layer 45 is formed on HSG silicon 44, followed by the formation of a second capacitor cell plate made of conductive layer 46.
FIGS. 3a, 3b, 3c and 4a, 4b represent steps that may integrated into semiconductor wafer fabrication and in particular DRAM fabrication to form storage capacitors. Conventional steps know to those skilled in the art may be used to fabricate the wafer up to the construction of the structures of FIGS. 3a and 4a. In like manner, after the formation of the HSG silicon, as depicted in 3b, 3c and 4b, the wafer is completed using conventional fabrication process steps.
It is to be understood that although the present invention has been described with reference to a preferred embodiment, various modifications, known to those skilled in the art, may be made to the structures and process steps presented herein without departing from the invention as recited in the several claims appended hereto.

Claims (54)

What is claimed is:
1. A thermal process for forming hemispherical grained silicon on a silicon material comprising the sequential steps of:
heating said silicon material to a steady state temperature;
exposing said silicon material to a hydrogen containing ambient; and
decreasing the temperature of said silicon material while exposing said silicon material to a silicon hydride gas.
2. The process as recited in claim 1, wherein said process further comprises a thermal cycle having a temperature ramp up period, a temperature steady state period during at least a portion of which said H2 ambient is present and temperature ramp down period during at least a portion of which said diluted silicon hydride gas is present.
3. The process of claim 1, wherein said silicon material is increased in temperature from a lower temperature to said steady state temperature.
4. The process as recited in claim 1, wherein said thermal process is a rapid thermal processing.
5. The process as recited in claim 1, wherein said thermal process comprises the use at least one furnace having a temperature ramp rate in the range of 6° C./min to 40° C./min.
6. A process for forming hemispherical grained silicon on a silicon material comprising the steps of:
heating said silicon material in an H2 ambient;
exposing said silicon material to a silicon hydride gas; and
decreasing the temperature of said silicon material.
7. The process as recited in claim 6, wherein said process further comprises a thermal cycle having a temperature ramp up period, a temperature steady state period during at least a portion of which said H2 ambient is present and temperature ramp down period during at least a portion of which said diluted silicon hydride gas is present.
8. The process as recited in claim 6, wherein said silicon hydride gas is diluted with an inert gas.
9. The process as recited in claim 8, wherein said inert gas is a gas selected from the group consisting of Ar and N2.
10. The process as recited in claim 8, wherein said diluted silicon hydride gas comprises approximately 2% argon.
11. The process as recited in claim 7, wherein said thermal cycle is performed by rapid thermal processing.
12. The process as recited in claim 7, wherein said thermal cycle is performed in a furnace.
13. The process as recited in claim 12, wherein said furnace has a heat ramp rate in the range of 6° C./min to 40° C./min.
14. The process as recited in claim 6, wherein said silicon hydride gas comprises silane (SiH4).
15. The process as recited in claim 6, wherein said silicon hydride gas comprises disilane (Si2 H6).
16. The process as recited in claim 6, wherein said silicon material comprises hemispherical grained silicon.
17. The process as recited in claim 6, wherein said silicon material comprises polysilicon.
18. The process as recited in claim 6, wherein said silicon material comprises amorphous silicon.
19. The process as recited in claim 6, wherein said silicon material conductively doped with conductive impurities.
20. The process as recited in claim 19, wherein said conductive impurities are introduced in situ during formation of said silicon material.
21. The process as recited in claim 19, wherein said conductive impurities are introduced into said silicon material by implantation after said silicon material is formed.
22. The process as recited in claim 6, further comprising precleaning said silicon material prior to said heating of the silicon material.
23. The process as recited in claim 22, wherein said precleaning comprises subjecting said silicon material to a silicon surface cleaning gas during a temperature ranging from 25° C. to 1250° C.
24. The process as recited in claim 23, wherein said silicon surface cleaning gas comprises GeH4.
25. The process as recited in claim 23, wherein said silicon surface cleaning gas comprises NF3.
26. The process as recited in claim 23, wherein said silicon surface cleaning gas comprises using ultraviolet light in an ozone gas.
27. The process as recited in claim 23, wherein said silicon surface cleaning gas comprises vapor hydrofluoric acid.
28. The process as recited in claim 7, wherein said steady state temperature ranges from approximately 500° C. to 1100° C.
29. The process as recited in claim 7, wherein said temperature is in between 25° C. to 950° C.
30. A process for forming a hemispherical gained silicon surface on at least one capacitor plate, said process comprising the steps of:
increasing the temperature of said capacitor plate in an H2 containing ambient, said capacitor plate comprising a silicon material;
exposing a surface of said capacitor plate's silicon material to a silicon hydride gas; and
decreasing the temperature of said capacitor plate.
31. The process as recited in claim 30, wherein said process further comprises a thermal cycle having a temperature ramp up period, a temperature steady state period during a portion of which said H2 containing ambient is present and a temperature ramp down period during a portion of which said silicon hydride gas is present.
32. The process as recited in claim 30, wherein said silicon hydride gas is diluted with an inert gas.
33. The process as recited in claim 32, wherein said inert gas is a gas selected from the group consisting of Ar and N2.
34. The process as recited in claim 32, wherein said diluted silicon hydride gas comprises approximately 2% argon.
35. The process as recited in claim 30, wherein said thermal cycle is performed by rapid thermal processing.
36. The process as recited in claim 30, wherein said thermal cycle is performed in a furnace.
37. The process as recited in claim 36, wherein said furnace has a heat ramp rate in the range of 6° C./min to 40° C./min.
38. The process as recited in claim 30, wherein said silicon hydride gas comprises silane (SiH4).
39. The process as recited in claim 30, wherein said silicon hydride gas comprises disilane (Si2 H6).
40. The process as recited in claim 30, wherein said silicon material comprises hemispherical grained silicon.
41. The process as recited in claim 30, wherein said silicon material comprises polysilicon.
42. The process as recited in claim 30, wherein said silicon material comprises amorphous silicon.
43. The process as recited in claim 30, wherein said silicon material is conductively doped with conductive impurities.
44. The process as recited in claim 43, wherein said conductive impurities are introduced in situ during formation of said silicon material.
45. The process as recited in claim 43, wherein said conductive impurities are introduced into said silicon material by implantation after said silicon material is formed.
46. The process as recited in claim 30, further comprising precleaning said silicon material prior to said heating of the silicon material.
47. The process as recited in claim 46, wherein said precleaning comprises subjecting said silicon material to a silicon surface cleaning gas during a temperature ranging from 25° C. to 1250° C.
48. The process as recited in claim 47, wherein said silicon surface cleaning gas comprises GeH4.
49. The process as recited in claim 47, wherein said silicon surface cleaning gas comprises NF3.
50. The process as recited in claim 47, wherein said silicon surface cleaning gas comprises using ultraviolet light in the presence of ozone gas.
51. The process as recited in claim 47, wherein said silicon surface cleaning gas comprises vapor hydrofluoric acid.
52. The process as recited in claim 31, wherein said steady state temperature period ranges from approximately 500° C. to 1100° C.
53. The process as recited in claim 31, wherein said temperature ramp up period ranges in temperature between 25° C. to 950° C.
54. The process as recited in claim 30, wherein said process further comprises:
forming a dielectric layer on said capacitor plate; and
forming a second capacitor plate on said dielectric layer.
US08/496,722 1995-06-29 1995-06-29 Method to thermally form hemispherical grain (HSG) silicon to enhance capacitance for application in high density DRAMs Expired - Lifetime US5663090A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US08/496,722 US5663090A (en) 1995-06-29 1995-06-29 Method to thermally form hemispherical grain (HSG) silicon to enhance capacitance for application in high density DRAMs
US08/842,302 US5913127A (en) 1995-06-29 1997-04-23 Method to thermally form hemispherical grain (HSG) silicon to enhance capacitance for application in high density DRAMS

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US08/496,722 US5663090A (en) 1995-06-29 1995-06-29 Method to thermally form hemispherical grain (HSG) silicon to enhance capacitance for application in high density DRAMs

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US08/842,302 Continuation US5913127A (en) 1995-06-29 1997-04-23 Method to thermally form hemispherical grain (HSG) silicon to enhance capacitance for application in high density DRAMS

Publications (1)

Publication Number Publication Date
US5663090A true US5663090A (en) 1997-09-02

Family

ID=23973843

Family Applications (2)

Application Number Title Priority Date Filing Date
US08/496,722 Expired - Lifetime US5663090A (en) 1995-06-29 1995-06-29 Method to thermally form hemispherical grain (HSG) silicon to enhance capacitance for application in high density DRAMs
US08/842,302 Expired - Fee Related US5913127A (en) 1995-06-29 1997-04-23 Method to thermally form hemispherical grain (HSG) silicon to enhance capacitance for application in high density DRAMS

Family Applications After (1)

Application Number Title Priority Date Filing Date
US08/842,302 Expired - Fee Related US5913127A (en) 1995-06-29 1997-04-23 Method to thermally form hemispherical grain (HSG) silicon to enhance capacitance for application in high density DRAMS

Country Status (1)

Country Link
US (2) US5663090A (en)

Cited By (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5770500A (en) * 1996-11-15 1998-06-23 Micron Technology, Inc. Process for improving roughness of conductive layer
US5821152A (en) * 1997-05-21 1998-10-13 Samsung Electronics Co., Ltd. Methods of forming hemispherical grained silicon electrodes including multiple temperature steps
US5863602A (en) * 1996-06-03 1999-01-26 Nec Corporation Method for capturing gaseous impurities and semiconductor device manufacturing apparatus
US5874333A (en) * 1998-03-27 1999-02-23 Taiwan Semiconductor Manufacturing Company, Ltd. Process for forming a polysilicon layer having improved roughness after POCL3 doping
US5902124A (en) * 1997-05-28 1999-05-11 United Microelectronics Corporation DRAM process
US5913127A (en) * 1995-06-29 1999-06-15 Micron Technology, Inc. Method to thermally form hemispherical grain (HSG) silicon to enhance capacitance for application in high density DRAMS
US5913128A (en) * 1995-07-24 1999-06-15 Micron Technology, Inc. Method for forming texturized polysilicon
US5930625A (en) * 1998-04-24 1999-07-27 Vanguard International Semiconductor Corporation Method for fabricating a stacked, or crown shaped, capacitor structure
US5980770A (en) * 1998-04-16 1999-11-09 Siemens Aktiengesellschaft Removal of post-RIE polymer on Al/Cu metal line
US6114229A (en) * 1998-11-20 2000-09-05 Advanced Micro Devices, Inc. Polysilicon gate electrode critical dimension and drive current control in MOS transistor fabrication
US6117692A (en) * 1997-01-14 2000-09-12 Kim; Young-Sun Calibrated methods of forming hemispherical grained silicon layers
US6153462A (en) * 1998-02-27 2000-11-28 Mosel Vitelic Inc. Manufacturing process and structure of capacitor
US6165841A (en) * 1998-06-09 2000-12-26 Samsung Electronics Co., Ltd. Method for fabricating capacitors with hemispherical grains
US6177309B1 (en) 1998-06-15 2001-01-23 Samsung Electronics Co., Ltd. Methods of forming integrated circuit capacitors having merged annular storage electrodes therein
US6184079B1 (en) 1997-10-31 2001-02-06 Samsung Electronics Co., Ltd. Method for fabricating a semiconductor device
US6190992B1 (en) * 1996-07-15 2001-02-20 Micron Technology, Inc. Method to achieve rough silicon surface on both sides of container for enhanced capacitance/area electrodes
DE19802523C2 (en) * 1997-10-18 2001-03-29 United Microelectronics Corp Process for the production of a structure from hemispherical silicon grain
US6218260B1 (en) 1997-04-22 2001-04-17 Samsung Electronics Co., Ltd. Methods of forming integrated circuit capacitors having improved electrode and dielectric layer characteristics and capacitors formed thereby
US6238968B1 (en) 1999-03-18 2001-05-29 Samsung Electronics Co., Ltd. Methods of forming integrated circuit capacitors having protected layers of HSG silicon therein
US6303956B1 (en) 1999-02-26 2001-10-16 Micron Technology, Inc. Conductive container structures having a dielectric cap
US6358793B1 (en) 1999-02-26 2002-03-19 Micron Technology, Inc. Method for localized masking for semiconductor structure development
US6385020B1 (en) 1999-01-20 2002-05-07 Samsung Electronics Co., Ltd. Methods of forming HSG capacitors from nonuniformly doped amorphous silicon layers and HSG capacitors formed thereby
US6639266B1 (en) 2000-08-30 2003-10-28 Micron Technology, Inc. Modifying material removal selectivity in semiconductor structure development
EP1455384A2 (en) * 1997-09-10 2004-09-08 Samsung Electronics Co., Ltd. An apparatus for fabricating a semiconductor device and a method for fabricating a polysilicon film using the same
US6902939B2 (en) * 1998-09-09 2005-06-07 Texas Instruments Incorporated Integrated circuit and method
US7101771B2 (en) 2000-04-04 2006-09-05 Micron Technology, Inc. Spin coating for maximum fill characteristic yielding a planarized thin film surface
US20060223333A1 (en) * 2005-04-05 2006-10-05 Ming Li Single wafer thermal CVD processes for hemispherical grained silicon and nano-crystalline grain-sized polysilicon
US20150373850A1 (en) * 2014-06-24 2015-12-24 Fujitsu Limited Electronic component, method of manufacturing electronic component, and electronic device

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3269531B2 (en) * 1998-01-30 2002-03-25 日本電気株式会社 Method for manufacturing semiconductor device
US6762136B1 (en) 1999-11-01 2004-07-13 Jetek, Inc. Method for rapid thermal processing of substrates
AU4134401A (en) * 1999-11-01 2001-06-06 Jetek, Inc. Method for rapid thermal processing of substrates
CN106504976B (en) * 2015-09-07 2019-05-03 中芯国际集成电路制造(上海)有限公司 The cleaning method of reflux board cavity

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4906590A (en) * 1988-05-09 1990-03-06 Mitsubishi Denki Kabushiki Kaisha Method of forming a trench capacitor on a semiconductor substrate
US5037773A (en) * 1990-11-08 1991-08-06 Micron Technology, Inc. Stacked capacitor doping technique making use of rugged polysilicon
US5278091A (en) * 1993-05-04 1994-01-11 Micron Semiconductor, Inc. Process to manufacture crown stacked capacitor structures with HSG-rugged polysilicon on all sides of the storage node
JPH0645521A (en) * 1992-07-24 1994-02-18 Miyazaki Oki Electric Co Ltd Manufacture of semiconductor element
US5290729A (en) * 1990-02-16 1994-03-01 Mitsubishi Denki Kabushiki Kaisha Stacked type capacitor having a dielectric film formed on a rough surface of an electrode and method of manufacturing thereof
US5302540A (en) * 1991-11-16 1994-04-12 Samsung Electronics Co., Ltd. Method of making capacitor
US5340765A (en) * 1993-08-13 1994-08-23 Micron Semiconductor, Inc. Method for forming enhanced capacitance stacked capacitor structures using hemi-spherical grain polysilicon
US5366917A (en) * 1990-03-20 1994-11-22 Nec Corporation Method for fabricating polycrystalline silicon having micro roughness on the surface
US5407534A (en) * 1993-12-10 1995-04-18 Micron Semiconductor, Inc. Method to prepare hemi-spherical grain (HSG) silicon using a fluorine based gas mixture and high vacuum anneal
US5444013A (en) * 1994-11-02 1995-08-22 Micron Technology, Inc. Method of forming a capacitor
US5500388A (en) * 1993-06-30 1996-03-19 Tokyo Electron Kabushiki Kaisha Heat treatment process for wafers
US5518948A (en) * 1995-09-27 1996-05-21 Micron Technology, Inc. Method of making cup-shaped DRAM capacitor having an inwardly overhanging lip

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5663090A (en) * 1995-06-29 1997-09-02 Micron Technology, Inc. Method to thermally form hemispherical grain (HSG) silicon to enhance capacitance for application in high density DRAMs

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4906590A (en) * 1988-05-09 1990-03-06 Mitsubishi Denki Kabushiki Kaisha Method of forming a trench capacitor on a semiconductor substrate
US5290729A (en) * 1990-02-16 1994-03-01 Mitsubishi Denki Kabushiki Kaisha Stacked type capacitor having a dielectric film formed on a rough surface of an electrode and method of manufacturing thereof
US5366917A (en) * 1990-03-20 1994-11-22 Nec Corporation Method for fabricating polycrystalline silicon having micro roughness on the surface
US5037773A (en) * 1990-11-08 1991-08-06 Micron Technology, Inc. Stacked capacitor doping technique making use of rugged polysilicon
US5302540A (en) * 1991-11-16 1994-04-12 Samsung Electronics Co., Ltd. Method of making capacitor
JPH0645521A (en) * 1992-07-24 1994-02-18 Miyazaki Oki Electric Co Ltd Manufacture of semiconductor element
US5278091A (en) * 1993-05-04 1994-01-11 Micron Semiconductor, Inc. Process to manufacture crown stacked capacitor structures with HSG-rugged polysilicon on all sides of the storage node
US5500388A (en) * 1993-06-30 1996-03-19 Tokyo Electron Kabushiki Kaisha Heat treatment process for wafers
US5340765A (en) * 1993-08-13 1994-08-23 Micron Semiconductor, Inc. Method for forming enhanced capacitance stacked capacitor structures using hemi-spherical grain polysilicon
US5407534A (en) * 1993-12-10 1995-04-18 Micron Semiconductor, Inc. Method to prepare hemi-spherical grain (HSG) silicon using a fluorine based gas mixture and high vacuum anneal
US5444013A (en) * 1994-11-02 1995-08-22 Micron Technology, Inc. Method of forming a capacitor
US5518948A (en) * 1995-09-27 1996-05-21 Micron Technology, Inc. Method of making cup-shaped DRAM capacitor having an inwardly overhanging lip

Cited By (54)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5913127A (en) * 1995-06-29 1999-06-15 Micron Technology, Inc. Method to thermally form hemispherical grain (HSG) silicon to enhance capacitance for application in high density DRAMS
US5913128A (en) * 1995-07-24 1999-06-15 Micron Technology, Inc. Method for forming texturized polysilicon
US5863602A (en) * 1996-06-03 1999-01-26 Nec Corporation Method for capturing gaseous impurities and semiconductor device manufacturing apparatus
US6190992B1 (en) * 1996-07-15 2001-02-20 Micron Technology, Inc. Method to achieve rough silicon surface on both sides of container for enhanced capacitance/area electrodes
US6060355A (en) * 1996-11-15 2000-05-09 Micron Technology, Inc. Process for improving roughness of conductive layer
US5770500A (en) * 1996-11-15 1998-06-23 Micron Technology, Inc. Process for improving roughness of conductive layer
US6117692A (en) * 1997-01-14 2000-09-12 Kim; Young-Sun Calibrated methods of forming hemispherical grained silicon layers
US6876029B2 (en) 1997-04-22 2005-04-05 Samsung Electronics Co., Ltd. Integrated circuit capacitors having doped HSG electrodes
US6624069B2 (en) 1997-04-22 2003-09-23 Samsung Electronics Co., Ltd. Methods of forming integrated circuit capacitors having doped HSG electrodes
US20040033662A1 (en) * 1997-04-22 2004-02-19 Seung-Hwan Lee Integrated circuit capacitors having doped HSG electrodes
US6218260B1 (en) 1997-04-22 2001-04-17 Samsung Electronics Co., Ltd. Methods of forming integrated circuit capacitors having improved electrode and dielectric layer characteristics and capacitors formed thereby
US5821152A (en) * 1997-05-21 1998-10-13 Samsung Electronics Co., Ltd. Methods of forming hemispherical grained silicon electrodes including multiple temperature steps
US5902124A (en) * 1997-05-28 1999-05-11 United Microelectronics Corporation DRAM process
EP1455384A3 (en) * 1997-09-10 2004-10-20 Samsung Electronics Co., Ltd. An apparatus for fabricating a semiconductor device and a method for fabricating a polysilicon film using the same
EP1455384A2 (en) * 1997-09-10 2004-09-08 Samsung Electronics Co., Ltd. An apparatus for fabricating a semiconductor device and a method for fabricating a polysilicon film using the same
DE19802523C2 (en) * 1997-10-18 2001-03-29 United Microelectronics Corp Process for the production of a structure from hemispherical silicon grain
US6184079B1 (en) 1997-10-31 2001-02-06 Samsung Electronics Co., Ltd. Method for fabricating a semiconductor device
US6153462A (en) * 1998-02-27 2000-11-28 Mosel Vitelic Inc. Manufacturing process and structure of capacitor
US5874333A (en) * 1998-03-27 1999-02-23 Taiwan Semiconductor Manufacturing Company, Ltd. Process for forming a polysilicon layer having improved roughness after POCL3 doping
US6563154B1 (en) 1998-03-27 2003-05-13 Taiwan Semiconductor Manufacturing Company Polysilicon layer having improved roughness after POCl3 doping
US5980770A (en) * 1998-04-16 1999-11-09 Siemens Aktiengesellschaft Removal of post-RIE polymer on Al/Cu metal line
US5930625A (en) * 1998-04-24 1999-07-27 Vanguard International Semiconductor Corporation Method for fabricating a stacked, or crown shaped, capacitor structure
US6165841A (en) * 1998-06-09 2000-12-26 Samsung Electronics Co., Ltd. Method for fabricating capacitors with hemispherical grains
KR100283192B1 (en) * 1998-06-09 2001-04-02 윤종용 Method for manufacturing capacitor with hemi-spherical grains
US6177309B1 (en) 1998-06-15 2001-01-23 Samsung Electronics Co., Ltd. Methods of forming integrated circuit capacitors having merged annular storage electrodes therein
US6902939B2 (en) * 1998-09-09 2005-06-07 Texas Instruments Incorporated Integrated circuit and method
US6114229A (en) * 1998-11-20 2000-09-05 Advanced Micro Devices, Inc. Polysilicon gate electrode critical dimension and drive current control in MOS transistor fabrication
US6385020B1 (en) 1999-01-20 2002-05-07 Samsung Electronics Co., Ltd. Methods of forming HSG capacitors from nonuniformly doped amorphous silicon layers and HSG capacitors formed thereby
US7199415B2 (en) 1999-02-26 2007-04-03 Micron Technology, Inc. Conductive container structures having a dielectric cap
US20060244030A1 (en) * 1999-02-26 2006-11-02 Micron Technology, Inc. Conductive container structures having a dielectric cap
US7868369B2 (en) 1999-02-26 2011-01-11 Micron Technology, Inc. Localized masking for semiconductor structure development
US20090102018A1 (en) * 1999-02-26 2009-04-23 Micron Technology, Inc. Localized masking for semiconductor structure development
US6303956B1 (en) 1999-02-26 2001-10-16 Micron Technology, Inc. Conductive container structures having a dielectric cap
US6833579B2 (en) 1999-02-26 2004-12-21 Micron Technology, Inc. Conductive container structures having a dielectric cap
US6573554B2 (en) 1999-02-26 2003-06-03 Micron Technology, Inc. Localized masking for semiconductor structure development
US20020030220A1 (en) * 1999-02-26 2002-03-14 Micron Technology, Inc. Conductive container structures having a dielectric cap
US6946357B2 (en) 1999-02-26 2005-09-20 Micron Technology, Inc. Conductive container structures having a dielectric cap
US20060006448A1 (en) * 1999-02-26 2006-01-12 Micron Technology, Inc. Localized masking for semiconductor structure development
US7015529B2 (en) 1999-02-26 2006-03-21 Micron Technology, Inc. Localized masking for semiconductor structure development
US7468534B2 (en) 1999-02-26 2008-12-23 Micron Technology, Inc. Localized masking for semiconductor structure development
US20070284638A1 (en) * 1999-02-26 2007-12-13 Micron Technology, Inc. Conductive container structures having a dielectric cap
US20030205749A1 (en) * 1999-02-26 2003-11-06 Micron Technology, Inc. Localized masking for semiconductor structure development
US7298000B2 (en) 1999-02-26 2007-11-20 Micron Technology, Inc. Conductive container structures having a dielectric cap
US6358793B1 (en) 1999-02-26 2002-03-19 Micron Technology, Inc. Method for localized masking for semiconductor structure development
US6238968B1 (en) 1999-03-18 2001-05-29 Samsung Electronics Co., Ltd. Methods of forming integrated circuit capacitors having protected layers of HSG silicon therein
US20070004219A1 (en) * 2000-04-04 2007-01-04 John Whitman Semiconductor device fabrication methods employing substantially planar buffer material layers to improve the planarity of subsequent planarazation processes
US7202138B2 (en) 2000-04-04 2007-04-10 Micron Technology, Inc. Spin coating for maximum fill characteristic yielding a planarized thin film surface
US20070004221A1 (en) * 2000-04-04 2007-01-04 John Whitman Methods for forming material layers with substantially planar surfaces on semiconductor device structures
US7101771B2 (en) 2000-04-04 2006-09-05 Micron Technology, Inc. Spin coating for maximum fill characteristic yielding a planarized thin film surface
US6639266B1 (en) 2000-08-30 2003-10-28 Micron Technology, Inc. Modifying material removal selectivity in semiconductor structure development
US20060223333A1 (en) * 2005-04-05 2006-10-05 Ming Li Single wafer thermal CVD processes for hemispherical grained silicon and nano-crystalline grain-sized polysilicon
US7341907B2 (en) 2005-04-05 2008-03-11 Applied Materials, Inc. Single wafer thermal CVD processes for hemispherical grained silicon and nano-crystalline grain-sized polysilicon
US20150373850A1 (en) * 2014-06-24 2015-12-24 Fujitsu Limited Electronic component, method of manufacturing electronic component, and electronic device
US9596767B2 (en) * 2014-06-24 2017-03-14 Fujitsu Limited Electronic component, method of manufacturing electronic component, and electronic device

Also Published As

Publication number Publication date
US5913127A (en) 1999-06-15

Similar Documents

Publication Publication Date Title
US5663090A (en) Method to thermally form hemispherical grain (HSG) silicon to enhance capacitance for application in high density DRAMs
US5656531A (en) Method to form hemi-spherical grain (HSG) silicon from amorphous silicon
US5407534A (en) Method to prepare hemi-spherical grain (HSG) silicon using a fluorine based gas mixture and high vacuum anneal
US5770500A (en) Process for improving roughness of conductive layer
US5418180A (en) Process for fabricating storage capacitor structures using CVD tin on hemispherical grain silicon
US5340765A (en) Method for forming enhanced capacitance stacked capacitor structures using hemi-spherical grain polysilicon
US5318920A (en) Method for manufacturing a capacitor having a rough electrode surface
US5885869A (en) Method for uniformly doping hemispherical grain polycrystalline silicon
JP2795313B2 (en) Capacitive element and method of manufacturing the same
US5882979A (en) Method for forming controllable surface enhanced three dimensional objects
JP3493627B2 (en) Method of manufacturing hemispherical granular polysilicon semiconductor structure
JPH10303368A (en) Manufacture of integrated circuit capacitor with improved electrode and dielectric layer property and capacitor produced thereby
US5573968A (en) Method for fabricating stacked capacitors of semiconductor device
US5821152A (en) Methods of forming hemispherical grained silicon electrodes including multiple temperature steps
US5702968A (en) Method for fabricating a honeycomb shaped capacitor
US6376303B1 (en) Method of manufacturing a capacitor having oxide layers with different impurities and method of fabricating a semiconductor device comprising the same
US6121081A (en) Method to form hemi-spherical grain (HSG) silicon
US5976931A (en) Method for increasing capacitance
US6235613B1 (en) Method of producing HSG using an amorphous silicon disordered layer as a substrate
US5798280A (en) Process for doping hemispherical grain silicon
JPH03263370A (en) Semiconductor device and manufacture thereof
US6194281B1 (en) Methods of forming three-dimensional capacitor structures including ozone tetraethylorthosilicate undoped silicate
US5923989A (en) Method of fabricating rugged capacitor of high density DRAMs
KR100379331B1 (en) Bottom electrode of capacitor and fabricating method thereof
US5960279A (en) Method of fabricating a capacitor on a rugged stacked oxide layer

Legal Events

Date Code Title Description
AS Assignment

Owner name: MICRON TECHNOLOGY, INC., IDAHO

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:DENNISON, CHUCK;THAKUR, RANDHIR P. S.;REEL/FRAME:007561/0897

Effective date: 19950629

AS Assignment

Owner name: MICRON TECHNOLOGY, INC., IDAHO

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:DENNISON, CHARLES H.;THAKUR, RANDHIR P.S.;REEL/FRAME:008513/0870

Effective date: 19970422

STCF Information on status: patent grant

Free format text: PATENTED CASE

CC Certificate of correction
FPAY Fee payment

Year of fee payment: 4

FPAY Fee payment

Year of fee payment: 8

FPAY Fee payment

Year of fee payment: 12